The objective of this program is to develop a superior X-ray detector for digital dental radiography, based on the technology of activated transparent optical ceramics. Progress has far exceeded our Phase I goals, producing a fully dense TOC whose light output as measured by CCDs is on a par with CsI:Tl. We have also developed a laser technique for pixelating this material, achieving an MTF at 12 1p/mm of 20%, a resolution twice as good as a Gd2O2S:Tb screen. Phase II will address three critical areas: We will maximize the light output by defining the optimal ceramic composition and treatment, with special attention to developing a commercially viable synthesis technique. We will improve the pixelization process so as to etch an array of 50 microm square pixels separated by grooves no more than 2.5 microm wide and an aspect ratio of at least 50:1, so as to reach a screen fill factor of at least 90%, and develop a system for achieving this at a speed appropriate for large-scale production. And we will fabricate, test, and evaluate prototype units under real life conditions. These results will form a solid foundation for Phase II industrial exploitation. PROPOSED COMMERCIAL APPLICATION: Because currently available X-ray phosphor screens cannot provide the necessary spatial resolution, medical radiography has been unable to tap the full potential of digital techniques for data acquisition and processing. The development of a material that can fill this need will revolutionize radiological techniques and greatly enhance their diagnostic power. The immediate market includes not only the entire dental community, but also other radiographic imaging such as tomography, and potentially extends to virtually every X-ray machine now in use.